Automatic sewing machine controller

ABSTRACT

An automatic sewing machine control apparatus having a machine needle  8  which is interlocked with a motor for use in sewing cloth  12 , a biaxial driving mechanism  20  allowing a cloth hold-down portion  10  to be manually moved in both X- and Y-axis directions perpendicularly intersecting each other, encoders  224  and  226  for detecting the rotational angles of an X- and a Y-axis motor  124  and  126  for driving the biaxial driving mechanism  20 , X and Y coordinate value computing means for obtaining the values of coordinates X and Y from the origin of the biaxial driving mechanism  20  according to the values detected by the encoders  224  and  226 , RAM for storing the values of coordinates X and Y obtained by the X and Y coordinate computing means by manually moving the biaxial driving mechanism  20  to at least one of predetermined positions of the machine needle, and forming means for forming a seam pattern in a predetermined position corresponding to the kind of the seam received from a group of sewing condition setting keys  56.

TECHNICAL FIELD

This invention relates to an automatic sewing machine control apparatusfor forming seams by driving and controlling a cloth holding downportion for use in clamping an article to be sewn.

BACKGROUND ART

In order to stitch desired sewing patterns using industrial sewingmachines, sewing data corresponding to the sewing patterns is preparedand information for driving the sewing machines in accordance with theorder of performing sewing operations is held in storage media such asfloppy disks. While cloth as an article to be sewn is press-clampedaccording to the sewing data (information on sewing methods), apredetermined sewing pattern is automatically stitched by moving thecloth on a predetermined plane.

The sewing data includes a relative position displacement quantitybetween a machine needle per stitch for forming the sewing pattern andthe cloth, and control commands for controlling the sewing machine and amotor for driving the machine. The sewing data on one sewing pattern isformed as a collection of data per stitch.

A conventional automatic sewing machine will be described with referenceto FIGS. 7 and 8. In FIGS. 7 and 8, an automatic sewing machine 1comprises an interlocking motor 2 for vertically operating a machineneedle 8 via a belt 4, a cloth hold-down portion 10 for use in clampingcloth 12 as an article to be sewn mounted on a machine table 1 a, aswitchgear 18 such as a cylinder, for example, for opening and closingthe cloth hold-down portion 10 used for attaching and detaching thecloth 12, and a biaxial driving mechanism 20 for moving the cloth 12 inthe two axial directions X and Y together with the cloth hold-downportion 10.

The biaxial driving mechanism 20 has an origin detector 21 for detectingthe mechanical origin of the cloth hold-down portion 10 and is soarranged as to be moved in two axial directions of X and Y as an X- anda Y-axis motor 24 and 26 each having stepping motors are driven, thesprockets of the respective X- and Y-axis motors 24 and 26 being put ona belt.

A control portion 30 includes CPU 32 for use in controlling clothfeeding as well as the motor speed in the sewing machine, ROM 34 forstoring a procedure for executing the system of the CPU 32, RAM 36 forstoring the sewing data prepared in an operating portion 50, a drivingportion 40 for driving motors, and an interface 42 for electricallyconnecting the origin detector 21 and the operating portion 60.

The operating portion 50 includes numeric keys 52 for inputting lengthsof sewing seams, a group of setting keys 54 for designating a sewingstart point and the like, a group of sewing condition setting keys 56 askinds-of-seams inputting means for inputting idle feeding and kinds ofseams such as linear, arcuate, circular seams and the like, and inchingkeys 58 for inching the cloth hold-down portion 10 on the X- and Y-axis,including an X-axis and a Y-axis inching key for inching the biaxialdriving mechanism 20 on the X- and Y-axis. Further, the operatingportion 50 has a coordinate operating portion for obtaining X and Ycoordinate values by increasing and decreasing the number of pulses fromthe inching keys, and a display portion 60 formed of a liquid crystaldisplay for displaying the X- and Y-axis coordinate values.

The operation of the automatic sewing machine thus arranged will bedescribed with reference to FIGS. 7 to 11. In a case where pocket cloth13 as a sewing object is sewn to the cloth 12 so as to attain A→B→C→D→Esewing points from the origin by idle feedings shown in FIG. 9, therefollow the steps of operating the X-Y driving mechanism 20 as shown inFIG. 10 via the driving portion 40 to generate pulse commands bydepressing the X- and Y-axis inching ±keys, making the coordinateoperating portion compute the coordinate values of Xa and Ya at thepoint A according to the pulse command by moving the machine needle 8from the origin to the position of the point A, and storing thecoordinate values in the RAM 36 by depressing the setting key.

Similarly, there also follow the steps of, as shown in FIG. 10,operating the X-Y driving mechanism 20 by depressing the X- and Y-axisinching keys to operate the X-Y driving mechanism 20 to position themachine needle 8 at the point B, depressing the setting key and thelinear sewing key to store the coordinate values of Xb and Yb and thekind of sewing in the RAM 36, then positioning the machine needle 8 atthe point C, and depressing the setting key and the linear sewing key tostore the coordinate values of Xc and Yc and the kind of sewing in theRAM 36. The coordinate values at the points D and E are stored in theRAM 36 likewise.

As the automatic sewing machine control apparatus has thus beenarranged, the sewing patterns have been stored in the RAM 36 with theoperator's operation of the biaxial driving mechanism 20 to actuate theX and Y motors 8 and 9 by depressing the X- and Y-axis inching keys andthe like when sewing data is newly input to and stored in the RAM 36.However, it is impossible for the biaxial driving mechanism 20 to movequickly as the X and Y motors 8 and 9 only operate intermittently, whichnecessitates a great deal of time to prepare the sewing pattern data. Inparticular, when a large amount of data is input, a large amount of timeis necessary for processing the data.

As the automatic sewing machine control apparatus has thus beenarranged, the sewing patterns have been stored in the RAM 36 with theoperator's operation of the biaxial driving mechanism 20 to actuate theX and Y motors 8 and 9 by depressing the X- and Y-axis inching keys andthe like when sewing data is newly input to and stored in the RAM 36.However, it is impossible for the biaxial driving mechanism 20 to movequickly as the X and Y motors 8 and 9 only operate intermittently, whichnecessitates a great deal of time to prepare the sewing pattern data.Particularly when a large amount of data is input, there has developed aproblem from causing a good long time therefor to be taken.

In view of the above problems, it is therefore an object of the presentinvention to provide an automatic sewing machine control apparatus whichreduces the work of arranging an article to be sewn.

DISCLOSURE OF THE INVENTION

An object of the present invention made to solve the foregoing problemsis to provide an automatic sewing machine control apparatus which isintended to reduce the work of arranging an article to be sewn.

In order to accomplish the object above, an automatic sewing machinecontrol apparatus in the first aspect of the invention comprises:kinds-of-seams inputting means for inputting idle feeding and kinds ofseams such as linear, arcuate, circular seams and the like correspondingto the seam pattern of an article to be sewn, a cloth hold-down portionfor clamping the article, a machine needle which is interlocked with adriving motor for use in sewing the article, a biaxial driving mechanismallowing the cloth hold-down portion to be manually moved in both X- andY-axis directions perpendicularly intersecting each other, an X- and aY-axis motor for driving the biaxial driving mechanism, rotational angledetection means for detecting the rotational angles of the X- and Y-axismotors, X and Y coordinate value computing means for obtaining thecoordinate values of X and Y from the origin of the biaxial drivingmechanism according to the values detected by the rotational angledetection means, storage means for storing the X and Y coordinate valuesobtained by the X and Y coordinate computing means by manually movingthe biaxial driving mechanism to at least more than one predeterminedposition of the machine needle, and forming means for receiving thepredetermined position thereof and forming a seam pattern correspondingto the kind of the seam received from the kinds-of-seams inputtingmeans.

An automatic sewing machine control apparatus in the second aspect ofthe invention comprises: storage means for storing the values of atleast two of the reference coordinates, a cloth hold-down portion forclamping a sewing line beforehand or a sewing article to be sewndisplaying at least two points forming the sewing line, a machine needlewhich is interlocked with a driving motor for use in sewing the article,a biaxial driving mechanism allowing the cloth hold-down portion to bemoved in both X- and Y-axis directions perpendicularly intersecting eachother, an X- and a Y-axis motor for driving the biaxial drivingmechanism, rotational angle detection means for detecting the rotationalangles of the X- and Y-axis motors, X- and Y-axis coordinate valuecomputing means, means for computing the values of tilting X- andY-coordinates of the start and designate points on the basis of therotational angles detected by the rotational angle detection means bymoving the biaxial driving mechanism between at least two any givensewing line of the sewing article clamped by the cloth hold-down portionor otherwise moving the biaxial driving mechanism in between the twopoints of the sewing article, means for computing the tilting valuesobtained from the of the X- and Y-coordinates, and modifying means formodifying the tilting of the sewing pattern according the value obtainedfrom the tilting computing means.

An automatic sewing machine control apparatus in the third aspect of theinvention in addition to the second aspect thereof includes storagemeans which has been stored with sewable coordinates showing an areawhere sewing is possible, and decision means for deciding whether or noteach of the modified coordinates of the sewing pattern generated by themodifying means is within the sewable coordinate values.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an overall automatic sewing machine controlapparatus embodying the present invention.

FIG. 2 is a plan view of a cloth hold-down portion of the automaticsewing machine control apparatus shown in FIG. 1, while the clothhold-down portion is being manually moved.

FIG. 3 is a flowchart showing the operation of the automatic sewingmachine control apparatus shown FIGS. 1 and 2.

FIG. 4 is a plan view of an article to be sewn as what is exemplifyingthe invention.

FIG. 5 is a flowchart showing the automatic sewing machine shown in FIG.4.

FIG. 6 is a plan view of an article that is clamped by the clothhold-down portion as what is exemplifying another invention.

FIG. 7 is a perspective view of the overall automatic sewing machinecontrol apparatus.

FIG. 8 is a block diagram of an overall conventional automatic sewingmachine control apparatus.

FIG. 9 is a plan view of a sewing chart that is applied to cloth.

FIG. 10 a plan view of the vicinity of the cloth hold-down portion ofthe automatic sewing machine control apparatus shown in FIG. 7, thecloth hold-down portion being automatically moved.

FIG. 11 is a plan view of cloth of FIG. 8 that is sewn to the trouser.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the invention will now be described as follows:

Embodiment 1

Referring to FIG. 1, there is shown a block diagram of an embodiment ofthe invention. FIG. 1 is a block diagram of an overall automatic sewingmachine control apparatus embodying the invention; though like referencecharacters shown therein designate like parts and the descriptionthereof will be omitted. As shown in FIG. 1, inching keys 58 that haveconventionally been provided in the display portion 60 are omitted andotherwise a start switch 301 for turning off the driving portion 40 andturning on a control portion 30 other than the driving portion 40 isadditionally provided. The sewing machine also has three-phase inductionmotors for actuating X- and Y-axis driving mechanism 20 including an X-and a Y-axis motors 124 and 126, encoders 224 and 226 as means fordetecting the respective rotational angles of the X- and Y-axis motorsand also generating the predetermined number of pulses corresponding tothe rotational angles thereof. The control portion 30 is provided withX- and Y-coordinate computing means (CPU 32 and ROM 34) for computing X-and Y-coordinate values of a machine needle 8 with respect to a clothhold-down portion 10 by increasing and decreasing the number of pulsesof encoders 224 and 226.

With the automatic sewing machine control apparatus thus arranged, itsoperation will now be described with reference to FIGS. 1 to 3. When apocket 13 as a sewing object is sewn to cloth 12 as shown in FIGS. 9 and11, that is, to attain sewing points A→B→C→D→E after idle feeding fromthe origin, a start switch 301 is turned on to turn off the drivingportion 40 so as to turn on the control portion 30 other than thecontrol portion 40 (Step S101). Then the cloth hold-down portion 10 ismanually moved to operate the biaxial driving mechanism 20 to move themachine needle 8 from the origin to the position of the point A (StepS105). At this time, the CPU 32 takes in an output signal via aninterface 42 by detecting the rotational angles of X- and Y-axis motors124 and 126 by using the encoders 224 and 226 (Step S107) whereby theCPU 32 uses the output signal to compute the values of coordinates Xaand Ya at the point A (Step S109). The values of coordinates Xa and Yathus computed are stored in the RAM 36 (Step S111) as idle data from theorigin up to the point A when the ‘idle key’ and the ‘input key’ aredepressed.

Similarly, the machine needle 8 is moved from the points A to B (Step SI13) by manually moving the cloth hold-down portion 10 to operate thebiaxial driving mechanism 20. The CPU 32 executes the Steps S107 andS109 (Step S115) while using forming means to form linear sewing data onsewing conditions, that is, what has a seaming length of 1.0 mm andstores the data in the RAM 36 (Step S117) when the ‘line key’, the seamlength ‘1.0’ mm, and the ‘input key’ are depressed.

Further, the biaxial driving mechanism 20 is operated by manually movingthe cloth hold-down portion 10 to move the machine needle 8 from thepoint B over the points C to D and E, and stores the values ofcoordinates at the points A→B→C→D→E, linear sewing data having a lengthof 1.0 mm (Step S117) when the ‘line key’, the seam length ‘1.0’ mm, andthe ‘input key’ are depressed.

Embodiment 2

Referring to FIGS. 4 and 5, there will be shown another embodiment ofthe invention, wherein the cloth 13 needs not to be preciselypositionally set to the cloth hold-down portion 10 so that the sewingstart point can be designated after the cloth 13 is set.

The RAM 36 is designed to store the values of coordinates PEn (Xn andYn) at each of the points in the area surrounded by, for example, asquare PEa→PEb1→PEc→PEd as an area that can be sewn beforehand, and eachof the coordinates is stored by inputting a numeric key 52 in theoperating portion 50. In this case, the point PEa (Xa and Ya) is takenas a coordinate origin. Further, the RAM 36 is stored with, for examplePo (Xo and Yo) and P1 (X1, Y1) as the values of at least two coordinatesobtained in the embodiment of the invention.

Now, the cloth 13 has been provided with sewing lines (may be at leasttwo points) with a point P′0 corresponding to the sewing start point andwith P0 (X0 and Y0) as the start point of the sewing pattern data storedin the RAM 36. The cloth 13 is then set at the approximate position(Step S201) and a start switch 301 is turned on to turn off the drivingportion 40 and the control portion 30 other than the driving portion 40is turned on (Step S203). The cloth hold-down portion 10 of the biaxialdriving mechanism 20 is manually moved whereby to align the sewing startpoint P′0 to the underside of the machine needle 8. The operatoroperates to depress the start key (Step S205).

With the CPU 32 using the output signals of the X and Y encoders 224 and226 as the coordinates P′0 (X′0 and Y′0) of the start point ′0, itcomputes the X′0 and Y′0.

When the operator judges that the sewing article pattern and the cloth13 are not parallel to each other (Step S207), the operator manuallymoves the cloth hold-down portion 10 so as to move the machine needle 8(Step S209) to any given point P′1 on a linear line connecting, forexample, the sewing start point P′0 to the next sewing reference pointP′1 (Step S209). The operator then depresses the input key (Step S211).

The CPU 32 reads the sewing start point P0 (X0 and Y0) and a sewingcurving point P1 (X1 and Y1) as two values of reference coordinates fromthe RAM 36 so as to obtain the tilting angle θ from the followingequation.

tan θ=(Y 1−Y 0)/(X 1−X 0)  (1)

As the line P0→P1 is parallel thereto as shown in FIG. 4, the tan θ isturned out to be zero.

Because of a point P′h (X′h and Y′h), the CPU 32 then obtains thetilting angle θ′ of sewing points of the cloth 13 at P′0→P′1 from thefollowing equation.

tan θ′=(Y′h−Y′0)/(X′h−X′0)  (2)

From the angles θ, θ′ above, an obtainable angle Δθ of an imaginaryreference line obtained from the reference coordinate values of theangles θ and θ′ above shifted from the sewing line in the cloth 13 setin the cloth hold-down portion 10 is as follows:

Δθ=θ′−θ  (3)

On condition that (n being 0, 1 . . . ) at any given point P, ′0, P′1, .. . as P′n (X′n, Y′n), each point is subjected to coordinate conversion(Step S213) using the following equation (4) according to the referencecoordinates Xn and Yn at each point stored in the RAM 36 so as to obtainnew reference coordinates.

X′n=Xx·cos Δθ+Yysin Δθ+X′0  (4)

Y′n=−Xx·sin Δθ+Yy·cos Δθ+X′0  (5)

wherein in the equations (4 and 5), Xx=Xn−X0, whereas

Yy=Yn−Y0.

The CPU 32 reads the values of the coordinates PEn (Xn and Yn) at eachpoint in the sewable area from the RAM 36 so as to judge whether or notthe new sewing reference point P′n (X′n and Y′n) and the passing pointare within the sewable area, and also whether or not the P′n subjectedto the coordinate conversion and the passing point PEn are within therange enclosed with the PEn (Step S215); if they are within the sewablerange, the P′n thus subjected to the coordinate conversion is stored inthe RAM 36 and the CPU 32 terminates the operation.

Although a description has been given of a linear pattern to be sewn inthe embodiment of the invention, the invention is also applicable to acurved pattern as shown in FIG. 6 with the modification of the tiltingof the cloth 13 as shown in a flowchart of FIG. 5 through the sameprocedure.

As set forth above, the invention according to the first aspect of theinvention has the effect of easily setting the sewing data at high speedas it is provided with the storage means for storing the X and Ycoordinate values obtained by the X and Y coordinate computing means bymanually moving the biaxial driving mechanism to at least more than onepredetermined position of the machine needle, and forming means forreceiving the predetermined position thereof and forming a seam patterncorresponding to the kind of the seam received from the kinds-of-seamsinputting means.

Moreover, the invention according to the third aspect of the inventionhas the effect in addition to what has been mentioned in the secondaspect of the invention of easily recognizing whether or not themodified sewing data exits in the sewable range as it is provided withthe storage means which has been stored with sewable coordinates showingan area where sewing is possible, and decision means for decidingwhether or not each of the modified coordinates of the sewing patterngenerated by the modifying means is within the sewable coordinatevalues.

Industrial Applicability

As set forth above, the automatic sewing machine control apparatus ofthe invention is suitable to reduce the work of arranging an article tobe sewn.

What is claimed is:
 1. An automatic sewing machine control apparatuscomprising: kinds-of-seam type inputting means for inputting an idlefeed and a seam type such as linear, arcuate, or circular seamscorresponding to the seam pattern of an article to be sewn, a clothhold-down portion for clamping the article, a machine needle which isinterlocked with a driving motor for use in sewing the article, abiaxial driving mechanism allowing the cloth hold-down portion to bemanually moved in both X- and Y-axis directions perpendicularlyintersecting each other, an X- and a Y-axis motor for driving thebiaxial driving mechanism, and rotational angle detection means fordetecting the rotational angles of the X- and Y-axis motors, X and Ycoordinate value computing means for obtaining the values of coordinatesX and Y from the origin of the biaxial driving mechanism according tothe values detected by the rotational angle detection means, storagemeans for storing the values of coordinates X and Y obtained by the Xand Y coordinate computing means by manually moving the biaxial drivingmechanism to at least more than one predetermined position of themachine needle, and forming means for forming a seam patterncorresponding to the seam type received from the seam type inputtingmeans.